Half (but only half) snarky answer (the other half is bitter disdain of the reality of bureaucracy):
Use vh
Everything is always sized to browser window.
Always allow scroll down, but disable horizontal scroll.
Set body width to be a static 50vh, and never code css that floats or breaks out of the parent div. (If they try to mock up something that looks like it does, clever use of a background gif can throw them off track.) And style only using tables so everything is held rigidly into place as expected. Include a javascript function to undo any ctrl+/- activity the user may do.
Users will hate you, because the site doesn't flow differently based on what they're using (such as text being too small to read on phones). Your coworkers will hate you because nobody in their right mind does this and it will likely break their work (though not yours). Your programming professors will hate you because this is not a good idea. Your UX designer will hate you because it will reveal the corners they cut in designing UX mock-ups that they have to do in order to meet deadlines.
Nearly everyone will hate you, except the people who tell you to make things match the mock-up and to do so quickly. Those people, however (which generally include the project managers), will be ecstatic by your accuracy and fast turn around time. And everyone knows their opinion is the only one that matters to your paycheck.